module.exports = (totalSize, req, res)=>{
    const range = req.headers['range'];
    if(!range){
        return {code:200};
    }

    const sizes = range.match(/bytes=(\d*)-(\d*)/);
    const end = sizes[2]||totalSize-1;
    const start = sizes[1]||totalSize-end;

    if(start > end || start < 0 || end > totalSize){
        return {code:200};
    }

    res.setHeader('Accept-Ranges', 'bytes');
    res.setHeader('Content-Range',  `bytes ${start}-${end}/${totalSize}`);
    return {
        code:206,
        start:parseInt(start),
        end:parseInt(end)
    };
    
};
